The dramatic rise in obesity within the U.S. over the past two decades has led to an increase in Type 2 diabetes and related health disorders. The National Institutes of Health has responded by establishing a task force devoted to accelerating the progress in obesity research. In August of 2004 the task force established a strategic plan for obesity research including research targeted at breaking the link between obesity and its related health disorders. Increased abdominal adiposity is correlated with a defect in glucose homeostasis and associated with decreased insulin sensitivity of peripheral tissue. Skeletal muscle is an important site of insulin-stimulated glucose disposal and often the site of insulin resistance in obesity. The molecular mechanisms of skeletal muscle insulin resistance remain to be uncovered and this gap is the basis of this proposal. We have established a human skeletal muscle cell system that responds to physiologic stimuli in vitro. Additionally, we have established and validated an adipocyte / myocyte co-culture system to investigate the interplay between these two cell types. Our preliminary studies show that adipocytes have a profound effect on skeletal myocyte metabolic activities. Based on the successful completion of Phase I, we are eager to extend our research in Phase II by focusing on making the co-culture system commercially available. We will continue the optimization and characterization of two skeletal muscle cell systems using the following aims. Aim 1 will continue the optimization and characterization of isolated human skeletal muscle cells, establish quality control criteria, and validate contract research services using this system. Aim 2 is focused on establishing and validating the adipocyte/myocyte co-culture system for commercial availability. We will investigate the effects of donor demographics on each cell type in the co-culture, establish quality control criteria, and identify methods for shipping and customer co-culture maintenance. Aim 3 is to establish a repository of donor-matched skeletal muscle, subcutaneous, and omental adipose tissue from patients of different demographics. These tissues and derived cells will be made available to researchers in the obesity and diabetes research fields. PUBLIC HEALTH RELEVANCE: At the completion of this project, a commercially available, fully validated human skeletal myocyte system, skeletal myocyte / adipocyte co-culture system, and related assay kits will be offered to researchers. The availability of these systems will provide opportunities for new approaches in the investigation of metabolic disease and a unique methodology to examine the complex interaction between these two cell types.